Horizontal extrusion presses are used for forming relatively long bar and tubular metal products, such as angles, "I" beams and channels. Horizontal presses are preferred in order to simplify removal of the bars and tubes which are susceptible to bending.
The horizontal extrusion press members include spaced apart fixed front and rear platens which are connected by long slender tie bars. Rams are slidably mounted in the rear platens and extrude metal ingots through dies which are mounted in the front platens. The metal ingots (generally aluminum alloys) are heated in furnaces to high temperatures and extruded under high forces through dies.
Alignments and inspections of extrusion presses are difficult because of the temperatures, forces, span between platens, and long slender tie rods. Current procedures utilize squares, levels, dial indicators, optical telescopes, inside micrometers and long wires.
There are a number of drawbacks with current procedures. One drawback is that data plots are unavailable for evaluating the twist, bend and flatness of rails and formulating the proper steps for correcting misalignments. Another drawback is that the current procedures require the extensive use of skilled personnel. Another drawback is that current procedures often fail to correct tracking and misalignment errors of rams with respect to furnaces and extrusion dies. Ram tracking and misalignment errors accelerate machine wear and die wear. Machine wear and die wear are undesirable because they cause frequent production losses, high maintenance costs and poor part quality.